Rotary engine.



W. N. ALLAN.

ROTARY ENGINE.

APPLIOATION FILED JAN.12, 1911.

1,053,767, Patented Feb. 18, 1913.

W. N. ALLAN.

ROTARY ENGINE.

LIO TION FILED JAN 12,1911

Patented Feb. 18, 1913.

SHEETS-SHEET 2.

/ fl A EL W. N. ALLAN.

ROTARY ENGINE.

APPLICATION FILED JAN. 12, 1911. 1,053,767. Patented Feb. 18, 1913.

3 BHBETB-BHBET 3.

I I up III/111d. A'///I/III WILLIAM N. ALLAN, OF SAN ANTONIO, TEXAS.

ROTARY ENGINE.

Specification of Letters Patent.

Patented Feb. 18, 1913.

Application filed January 12, 1911. Serial No. 602,211.

To all whom it may concern Be it known that I, \VILLIAM N. ALLAN, a citizen of the United States, residing at San Antonio, in the county of Bexar and State of Texas, have invented new and useful Improvements in Rotary Engines, of which the following is a specification.

My present invention relates to improvements in rotary engines adapted to use steam or other expansible fluid as a motive agent, and it has for its objects to provide a multiple cylinder engine of this type wherein the pistons and the means for admitting and exhausting the steam or motive fluid are so related in the different piston chambers as to insure uniform turning effort of the engine shaft and smooth running of the engine, the engine being self-starting, and it is also an object of the present invention to provide improved means for admitting and expanding the steam or motive fluid within each piston chamber whereby greater efficiency in the operation of the engine is obtained.

0 these and other ends, the invention consists in certain improvements, and combinations and arrangements of parts, all as will be hereinafter more fully described, the novel features being pointed out particularly in the claims at the end of the specification.

In the accompanying drawing: Figure 1 represents a transverse section of a rotary engine constructed in accordance with one embodiment of my invention, a portion of one of the pistons being broken away; Fig. 9. represents a longitudinal vertical section of the engine on the line '2-2 of Fig. 1; Figs. 3 and 4 represent sections on the lines and l-it respectively of Fig. 1; Fig. 5 represents an axial section through the assembled pistons; Fig. (i is a detail perspec tive view of one of the fluid-controlling abntments of the casing; Fig. 7 represents a longitudinal sect-ion of one of the piston slides; Fig. 8 is a perspective view of one of the piston slides removed from the piston; Fig. 9 represents a dctail transverse section of the upper portion of the engine showing a modification of the means for admitting the steam or motive fluid to the pistons whereby the engine may be reversed; Fig. 10 represents a longitudinal section of the valve and the adjacent portion of the casing as shown in Fig. 9; Fig. 11 is an exterior end elevation of the upper portion of the engine as shown in Fig.0, the same, however, being on a reduced scale; Fig. 12 is a detail perspective view of one of the duplex valves which is operated in reversing the engine; and Fig. 13 is a detail view of one of the valves which may be used in admitting the motive fluid at full pressure and directly to the pistons in emergencies to increase the power of the engine.

Similar parts are designated by the same reference characters in the several views.

In the accompanying drawing I have shown certain embodiments of the invention, but. it will be understood that these are shown as examples, as modifications and changes may be made in the detail construe tion and proportions or the relative arrangement of the parts in order that the basic features of the invention may be applied to the best advantage.

In that form of the invention shown in Figs. 1 to S inclusive, the engine embodies a casing 1 which may be constructed in any suitable way and is provided with piston chambers of a number corresponding to the number of pistons to be used. In that form of the invention shown, a set of four piston chambers 2 are used which correspond to the four pistons 8. Any suitable construction may be adopted for the casing, it

being built up in the present instance of units embodylng rings 1 the interiors of which constitute the piston chambers, cir- :nlar partitions 5 are interposed between the rings 4, heads (3 are applied and close the opposite ends of the casing, and the whole structure is united firmly by longitudinal bolts 7 placed at suitable intervals, as shown in Fig. 1. The pistons are assembled concentrically upon the engine shaft 8, they being keyed thereto as usual, or the intermediate portion of the shaft may he squared as shown so that all the pistons will revolve as a unit. The pistons 3 have cylindrical peripheries and they may be formed as duplicates. In those cases where four pistons are used each piston will be formed with a supply or feed groove 9 for the motive fluid which extends around slightly more than one quarter of the circumference of the piston, and the pistons are so applied to the shaft that one feed groove is receiving the motive fluid during the first quarter revolution of the shaft whereupon the motive fluid is cut off from the correspending piston and is admitted to another piston during the next quarter revolution of the shaft, this being continued through each revolution of the shaft to the end that steam is being admitted to the piston chambers successively and during each quarter revolution.

Each piston is provided at the end of its respective motive fluid supply groove With a slide 10 which. operates radially in a recess 11 formed in the respective piston and during the major portion of the revolution of each piston, its respective slide projects out wardly beyond the piston and into the piston chamber. In the present instance each piston slide is guided by a pair of rods 12 which are contained in the recess 11 of the piston and operate freely in bores 13 formed in the slide, and springs 14 encircle each rod and operate to yieldingly press each slide outwardly so as to maintain a steam-tight joint between its outer end and the inner circumference of its respective piston cham i ber. To prevent leakage of the motive fluid past the end and two sides of each slide, the latter is provided with a set of four packing strips 15 which operate in grooves which are formed in the outer end, the two sides, and the rear face of the slide, and in order to enable these packing strips to shift rela tively to each other to maintain a tight joint but to prevent leakage of the motive fluid. past the ends of the strips, I provide the strips with interengaging tongues 16 as shown in detail in Fig. 8. It is to be understood-that the slides 10 on the several pistons are placed at ninety degrees apart as indicated diagrammatically in Fig. 1. To

' prevent leakage of the motive fluid from one piston chamber to another I prefer to interpose disks 17 between the several pistons 3 and to also apply similar disks at the ends of the pistons, and these disks are grooved circumferentially and provided with packing strips 18 which cooperate with the inner circumferences of the partitions 5 of the casing. The concentrically arranged pistons 3 and the interposed disks are rigidly united so as to revolve as a unit by a suitable number of axially extending bolts 19 as shown in Fig. 5. In order to maintain the packing strips 15 on each piston slide in fluid-tight engagement with the walls of the piston chamber and also with one wall of the recess 11, springs 20 are preferably placed in the grooves 21 of the slide which contains these strips and the strips may be also held from displacement by pins 22 attached to the stripsand operating in bores 23 formed in the slide as shown in detail in Fig. 7

The ends of the shaft 8 extend through the heads 6 and the escape of steam from the casing around the shaft is prevented by stuffing boxes 24. This shaft may be journaled or supported in any suitable way, the

heads 6 serving such purpose, if desired, or if preferred, separate standards 25 may be provided as shown. A power transmitting pulley or its equivalent 26 is fixed to the shaft and if desired a balance wheel 27 may also be used.

The major portion of each piston chamher is cylindrical and concentric with the shaft 8 in order that the steam or motive fluid may be worked expansively during the major portion of the rotation of each piston, as will be hereinafter described. The upper part of the casing, however, is provided with an abutment 28 which extends inwardly to the several pistons. A longitudinally extending passage 29 is formed in this abutment which receives the motive fluid or live steam from a supply pipe 30, and ports 31 establish communication between this chamber 29 and the several piston chambers. An exhaust passage 32 is also formed in the abutment of the casing and is common to all the piston chambers whereby the steam or motive fluid is discharged therefrom and into the exhaust pipe 32 In operation the groove 9 of each piston receives the steam or motive fluid from its respective port 31 during slightly more than a quarter revolution of this particular piston. Means is prothe exhaust passage. The inner portion of the abutment 28 is provided with a set of recesses which contain a set of slidable packing devices 33, 34 and 35 which cooperate wit-h the periphery of the corresponding piston. The packing device 33 is preferably common to all the pistons and it is yieldably pressed into engagement with the cylindrical circumferences of the pistons by the springs 36 and it is guided by the pins 37. Each packing device 34, however, is relatively narrow and adapted to operate in the groove 9 of the respective piston, it being yieldably pressed inwardly by a spring 38 which encircles a guiding pin 39 attached to the packing device. tight connection between this packing device 34 and the bottom and sides of the groove 9, such packing device is preferably provided In order to insure a steam with a packing strip 40 which is similar to j with the piston and it is guided by a pin 42.

A packing strip 35 also cotiperates with the periphery of each piston at the opposite side of the port 31. To minimize friction and prevent binding of each piston slide in its respectit e recess, a pair of antifriction rollers 43 and 44 are journaled in the recess and cooperate with the forward and rear sides of the slide.

In operating a rotary engine of the construction just described, the steam or motive fluid is fed from the passage 29 successively to the piston chambers through the ports 31. As each piston reaches a position in which the forward end of the groove 9 in its circumference communicates with the steam supply port 31, steam from this port will flow from the port 31 through the groove 9 and will then enter the piston chamber and will act upon the corresponding piston slide 10, and steam or motive fluid will continue to enter the piston chamber at substantially boiler pressure until the rear end of the groove 9 passes the corresponding supply port 31 whereupon the admission of steam to this particular piston chamber will be discontinued and steam will then begin to enter another piston chamber. After the admission of steam has been discontinued with respect to one of the piston chambers, the steam that has been admitted will be trapped and will work expansively in propelling the piston during the remainder of its revolution, and when each revolution of the piston has been com leted, the expanded steam will be exhaustec from the piston chamber through the exhaust passage 32.

I have shown in Figs. 9 to 13 inclusive a rotary engine embodying substantially the principles involved in the construction pre viously described, but in this latter instance, the engine is reversible, that is to say, it may be operated in either direction. In this instance each piston 45 is cylindrical and concentric with respect to its shaft 46 as in the previous instance, but the periphery of the piston has no steam supply groove. Each piston has, however, a slide 47 which operates radially in a recess 48 formed in the piston and it is pressed outwardly by one or more springs 49 each of which surrounds a guiding stem or rod 50. The outer portion of the slide in this instance is preferably provided with two packing devices 51 and 52 and two pairs of anti-friction rollers 53 and 5-4 may be used in order that this slide may operate equally well, irrespective of the direction in which the piston is revolving. In this form of the invention the upper portion of the casing is formed with a valve chest 55, this chest containing a revoluble cylindrical valve 56 which is driven by any suitable means in the same direction and at the same speed of rotation as the piston. In the present instance the outer end of the valve 56 is provided with a shaft 57 which projects to the exterior of the easing and is fitted with a sprocket wheel 58, and a chain 59 cotiperates with the sprocket wheel 58 and with a sprocket Wheel 60 on of each piston, and spring-presse the engine shaft. The upper portion of the engine casing is also formed with a partition wall 61 which bears upon the periphery c packing strips 62 are employed to prevent flow of steam from one side to the other side of the casing. Ports 63 and 64 are formed in the casing and lead to the piston chamber 65 therein at opposite sides of the partition wall 61. The port 63 is adapted to communicate with a steam supply passage 66 while the port 64 is adapted to communicate with a similar steam supply passage 67. These ports 63 and 64 are also adapted to communicate alternately with exhaust passages 68 and 69 which communicate with the exhaust pipe 69. Communication between the port 63 and the passages 66 and 68 and between the port 64 and the passages 67 and 69 is controlled, however, in each instance by a duplex valve which consists of a slide 70 having ports 71 therein corresponding to the number of pistons employed which control the admission of steam or motive fluid to the respective piston chambers, and a slide 72 which is interposed between the respective port and the exhaust passage and has ports 73 therein corresponding in number to the pistons employed. The 'ports 71 and 73 in the slides 70 and 72 are arranged in alternating relation, and the two slides are operatively connected to move in unison by the cotiperating arms 74. Both pairs of slides 70 and 72 respectively are operatively connected at 70 and 71 respectively to a hand lever 75 pivoted to the lug 76 on the exterior of the en ine casing so that when this lever is shifted in one direction it will shift the slides 70 and 72 at the right hand side of Fig. 9 in one direction to establish communication between the steam supply passage 67 and the port 64 leading to the piston chamber at one side of the v artition 61, and will simultaneously cut ofi communication between the port 64 and the exhaust passage 69 and at the same. time the slides 70 and 72 at the left hand side of Fig. 9 will be shifted in a reverse direction whereby communication will be established between the port 63 and the exhaust passage 68 and communication will be cut off between the port 63 and the steam supply passage 66 as shown in Fig. 9, and when this lever 75 is shifted into a reverse position the relation of the parts shown in Fig. 9 will be reversed and consequently the direction of rotation of the pistons will be reversed.

The revoluble valve 56 is formed with a set of grooves 77 which extend slightly more than quarter way around its circumference and the grooves for the different pis tons are spaced ninety degrees apart. The upper portion of the valve chest 55 is formed with a steam chamber 78 and a pair of ports 79 and 80 are adapted to establish communication between this steam chamber and the steam chambers 81 and 82. The steam chambers 81 and 82 are separated by a wall 83 and steam may be directed into either one of the chambers 81 and 82 by means of a slide valve 84 which is connected to be operated by a lever 85 on the exterior of the engine casing. Shifting of the valve 84 serves to reverse the direction of the engine, as will hereinafter appear. Steam or motive fluid when admited to either of the chambers 81 or 82 is prevented from escaping into the other chamber by means of spring-pressed packing devices 86 which cooperate with the cylindrical circumference of the valve and a narrower packing device 87 which cooperates with the groove 77 in the-valve, these packing devices being similar to those used to operate upon the piston in that form of the invention first described. Packing strips 86" also prevent leakage of steam from either of the chambers 81 or 82 to the ports 88 or 89. The steam supply passages 66 and 67 have ports 88 and 89 which lead inwardly to the periphery of the revoluble valve 56 and they are so placed that during rotation of the valve 56 steam will be supplied from the chamber 81 or 82 as the case may be through the groove 77 in the valve and into one of these ports 88 or 89.

In Fig. 9 the parts are shown in position for driving the piston in the direction indi cated by the arrow in which case steam is admitted from the chamber 78, through the 'port80, into the chamber 82 and from the latter, the steam flows through the groove 77 inrthe valve, into the inlet port 89, thence through the passage 67, through the opening 71 in the slide 70, into the port 6%, and thence into the piston chamber and behind the slide 47, the exhaust steam or motive fluid flowing from the piston chamber through the ports 68 and 7.3 and through the passage 68 and exhaust pipe 69 By reversing the position of the slide valve 84, the steam or motive fluid will enter the piston chamber through the port 63, thereby causing rotation of the piston in a reverse direction. In this instance the steam is admitted to each piston chamber during approximately one quarter revolution of the piston, the remaining portion of the revolution of each piston being efi'ected by expansive action of the steam. In some instances, however, it may be desirable in emergency to materially increase the power of the engine. This can be easily accomplished by extending the steam inlet passages 66 and 67 to form supplemental ports 90 and 91 which are adapted to communicate with the steam chambers 81 and 82 under the control of slide valves 92 and 93, these slide valves being operatively connected to handles or levers 9%. and 95 on the exterior of the engine casing. Each of these slide valves 92 and 93 have ports formed therein of a number corresponding to the number of pistons used and these valves will be normally in closed position during the expansive working of the engine. Assuming, however, that the engine is operating in the direction indicated by the arrow in Fig. 9 and that it is desirable to materially increase the power of the engine, this can be effected by shifting the slide 93 so as to uncover the port 91 in which case steam at full pressure would pass through the port 64 into the piston chamber during the complete revolution of the corresponding piston. Normally, however, the ports 90 and 91 are closed by the respective slides in order that efliciency may be obtained by working the steam expansively.

I claim as my invention: I

1. In an engine of the type described, the combination of a casing, a rotary member therein having a segmental groove in its periphery which extends partially around the circumference thereof, the casing having a motive fluid inlet leading to the periphery of said member, a packing device cooperative with the ungrooved portion ofthe periphery of said member at one side of said motive fluid inlet,- and packing devices cooperative with the grooved and ungrooved portions of the periphery of said member at the opposite side of said motive fluid inlet.

2. In a rotary engine, the combination of a casing providing a piston chamber, a'revoluble member mounted in the casing and having its periphery formed with a segmental groove which extends partially around its circumference, a piston slide carried by said member and adapted to be acted on by the motive fluid, the casing having a passage for supplying motive fluid to the periphery of said member, a packing device cooperative with the ungrooved periphery of said member at one side of said supply passage and bridging the groove in said 1nember, and packing devices cooperative with the periphery and the walls of the groove in said member at the opposite side of said supply passage whereby motive fluid is supplied to the piston slide through and under the control of said peripheral groove.

3. In a rotary engine, the combination of a casing provided with a plurality of piston chambers, a set of piston members revoluble in the respective chambers and having a set of grooves in their peripheries, said grooves being spaced at equal angles about the axis ofsaid members and each groove extending partially around the circumference of the respective member, a set of piston slides carried by said piston members, the slides for the different piston members being arranged at equal angles about their axis of revolution, the casing having ports for supplying M motive fluid to the grooved peripheries of the piston members, a packing device cooperative With the ungrooved periphery and bridging the groove of each piston member at one side of its respective motive fluid supply port and packing devices cooperative with the periphery and the bottom and side walls of the groove in each piston member at the opposite side of its respective motive fluid supply port whereby motive fluid is admitted successively to the piston slides through and under the control of said grooves.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

WILLIAM N. ALLAN. \Vitnesses WV. H. KENNON, IVALTER P. Norman.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, I). G. 

